A conventional method for bonding out lead bonding (OLB) pads and tape carrier package (TCP) pads is described below with reference to FIGS. 1 and 2. The dummy pad groups 10 and the data/gate pad group 20 are formed on a liquid crystal display (LCD) panel 100 as shown in FIG. 1. The dummy pad groups 10 are formed on both sides of data/gate pad group 20. Generally, each of the pads in groups 10 and 20 includes a metal pad 12 and a layer of indium tin oxide (ITO) 13 formed on one end portion of the respective metal pad 12. The dummy pad group also includes ITO dummy pads 30, wherein each of the ITO dummy pads includes only a layer of ITO.
Each of the ITO layers 13 and the ITO dummy pads 30 in each pad group 10 or 20 correspond to a respective TCP OLB pad 40, and are bonded by an anisotropic conductive layer (ACL) 50 therebetween, as shown in FIG. 2. The ITO layers 13 enable the pad groups 10 and 20 to be bonded with the TCP OLB pads 40, and the ITO dummy pads 30 enable the misalignment of the pads to be tested as the pads are bonded on the basis of the ITO dummy pad 30.
It may be difficult to test misalignment of the ITO dummy pad 30, however, because the ITO layer is transparent. In addition, measurement of any misalignment may be difficult because the pad pitch can become fine gradually. Accordingly, there continues to exist a need in the art for improved alignment tests which will allow increased productivity and reduced cost.